Ultrasensitive biosensors for probing protein structures could greatly improve diagnosis of a wide variety of diseases extending to both humans and animals. These include Alzheimer’s disease, Chronic Wasting Disease, and mad cow disease—disorders related to protein misfolding. Such biosensors could also lead to improved technologies for developing new pharmaceutical compounds.
“In order to detect and treat many diseases we need to detect protein molecules at very small amounts and understand their structure,” said Sang-Hyun Oh, University of Minnesota electrical and computer engineering professor and lead researcher on the study. “Currently, there are many technical challenges with that process. We hope that our device using graphene and a unique manufacturing process will provide the fundamental research that can help overcome those challenges.”
Significant attempts have been made to improve biosensors using graphene, but the challenge exists with its single atom thickness. This means it does not interact efficiently with light when shined through it. Light absorption and conversion to local electric fields is essential for detecting small amounts of molecules when diagnosing diseases. Previous research utilizing similar graphene nanostructures has only demonstrated a light absorption rate of less than 10 percent.
In this new study, University of Minnesota researchers combined graphene with nano-sized metal ribbons of gold. Using sticky tape and a high-tech nanofabrication technique developed at the University of Minnesota, called “template stripping,” researchers were able to create an ultra-flat base layer surface for the graphene.